Weight saving between the 2 is 100 front and 80 rear roughly. Julies are popular brakes for those on a budget, personally not used Magura brakes. Prices for both look high to me.
If you are stuck with either and no others to choose from consider what type of riding you are going to be doing and make your choice based on that.
Do you need the extra braking the Marta will give you?
The prices are basically what HP Velotechnik say, so no movement on that, at least not a lot.
Do I need the power = Probably not.
Do I want all the power I can get = yes.
Recumbent cycles have a much lower center of gravity, so can deal with more braking power than DF cycles.
What cycling will I be doing = it will be my only form of powered transport, so used for anything from a short run to the local shops, to long days/weekends out on the roads, but 99.9999% of the time not off road.